Project Gutenberg's The Boy's Book of New Inventions, by Harry E. Maule This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org Title: The Boy's Book of New Inventions Author: Harry E. Maule Release Date: July 9, 2014 [EBook #46232] Language: English Character set encoding: ISO-8859-1 *** START OF THIS PROJECT GUTENBERG EBOOK THE BOY'S BOOK OF NEW INVENTIONS *** Produced by Chris Curnow, Mary Akers and the Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) WILBUR WRIGHT Who with his younger brother, Orville Wright, invented the first practical aeroplane. Wilbur Wright's death of typhoid fever in the summer of 1912 was an irreparable loss to aviation i THE BOY'S BOOK OF NEW INVENTIONS BY HARRY E. MAULE MANY ILLUSTRATIONS Garden City New York DOUBLEDAY, PAGE & COMPANY 1912 Copyright, 1912, by Doubleday, Page & Company All rights reserved including that of translation into foreign languages, including the Scandinavian To My Mother In Appreciation of Her Broad Interest In All the Activities of the World ii iii iv ACKNOWLEDGMENTS The thanks of the publishers and author are due a great many individuals and publications for aid in securing photographs and data used in the preparation of this volume. Although space prevents giving the names of all, opportunity is here taken to express to each the heartiest appreciation of their generous help and valuable suggestions. More than to all of these are my thanks due my wife, Edna O'Dell Maule, for her constant aid and coöperation. v I PREFACE N THE preparation of this book the author has tried to give an interesting account of the invention and workings of a few of the machines and mechanical processes that are making the history of our time more wonderful and more dramatic than that of any other age since the world began. For heroic devotion to science in the face of danger and the scorn of their fellowmen, there is no class who have made a better record than inventors. Most inventions, too, are far more than scientific calculation, and it is the human story of the various factors in this great age of invention that is here set forth for boy readers. New discoveries, or new applications of forces known to exist, illustrating some broad principle of science, have been the chief concern of the author in choosing the subjects to be taken up in the various chapters, so that it has been necessary to limit the scope of the book, except in one or two instances, to inventions that have come into general use within the last ten years. In "The Boy's Book of Inventions," "The Second Boy's Book of Inventions," and "Stories of Invention," Mr. Baker and Mr. Doubleday have told the stories of many of the greatest inventions up to 1904, including those of the gasoline motor, the wireless telegraph, the dirigible balloon, photography, the phonograph, submarine boats, etc. Consequently for the most part the important developments in some of these machines are treated briefly in the final chapters, while the earlier chapters are devoted to new inventions, which, if made before 1904, did not receive general notice until after that time. Although the subjects treated in the earlier chapters are here spoken of as new inventions, all of them are not recent in the strictest sense of the word, for men had been working on the central idea of some of them for many years before they actually were developed to a stage where they could be patented and sent out into the world. H. E. M. vi vii CONTENTS CHAPTER PAGE I. THE AEROPLANE How a Scientist Who Liked Boys and a Boy Who Liked Science Followed the Fascinating Story of the Invention of the Aeroplane. 3 II. AEROPLANE DEVELOPMENT How the Inventors Carried On the Art of Aviation Until It Became the Greatest of All Sports and Then a Great Industry. 49 III. AEROPLANES TO-DAY Our Boy Friend and the Scientist Look Over Modern Aeroplanes and Find Great Improvements Over Those of a Few Years Ago. A Model Aeroplane. 91 IV. ARTIFICIAL LIGHTNING MADE AND HARNESSED TO MAN'S USE Our Friends Investigate Nikola Tesla's Invention for the Wireless Transmission of Power, by Which He Hopes to Encircle the Earth With Limitless Electrical Power, Make Ocean and Air Travel Absolutely Safe, and Revolutionize Land Traffic. 129 V. THE MOTION PICTURE MACHINE Machines That Make Sixteen Tiny Pictures Per Second and Show Them at the Same Rate Magnified Several Thousand Times. Motion Pictures in School. Our Boy Friend Sees the Whole Process of Making a Motion Picture Play. 164 VI. ADVENTURES WITH MOTION PICTURES Perilous and Exciting Times in Obtaining Motion Pictures. How the Machine Came to Be Invented and the Newest Developments in Cinematography. 195 VII. STEEL BOILED LIKE WATER AND CUT LIKE PAPER Our Boy Friend Sees How Science Has Turned the Greatest Known Heats to the Everyday Use of Mankind. 224 VIII. THE TESLA TURBINE Dr. Nikola Tesla Tells of His New Steam Turbine Engine, a Model of Which, the Size of a Derby Hat, Develops More Than 110 Horse Power. 263 IX. THE ROMANCE OF CONCRETE The One Piece House of Thomas A. Edison and Other Uses of the Newest and Yet the Oldest Building Material of Civilized Peoples, Seen By the Boy and His Scientific Friend. 288 X. THE LATEST AUTOMOBILE ENGINE Our Boy Friend and the Scientist Look Over the Field of Gasoline Engines and See Some Big Improvements Over Those of a Few Years Ago. 320 XI. THE WIRELESS TELEGRAPH UP TO THE MINUTE The Scientist Talks of Amateur Wireless Operators. The Great Development of Wireless That Has Enabled It to Save Three Thousand Lives. Long Distance Work of the Modern Instruments. 332 XII. MORE MARVELS OF SCIENCE Color Photography, the Tungsten Electric Lamp, the Pulmotor, and Other New Inventions Investigated by Our Boy Friend. 352 viii ix LIST OF ILLUSTRATIONS Wilbur Wright Frontispiece FACING PAGE The First Wright Aeroplane 4 The First Wright Glider 5 The Second Wright Glider 5 A Long Glide 5 Motor of the Wright Biplane 12 A 16-Cylinder, 100-Horsepower Antoinette Motor 12 An 8-Cylinder, 50-Horsepower Curtiss Motor 12 Standard Gnome Aeroplane Motor 13 A 14-Cylinder, 100-Horsepower Gnome Motor 13 Testing a Gnome Motor on a Gun Carriage 13 Model Aeroplane Fliers 16 A Modern College Man's Glider 17 Otto Lilienthal Making a Flight in His Glider 17 The Chanute Type Glider 32 The Herring Glider 32 An Early Helicopter 32 Prof. Samuel Pierpont Langley 33 Sir Hiram Maxim 33 Octave Chanute 33 Langley's Steam Model 36 The Maxim Aeroplane 36 Medals Won by the Wright Brothers 37 The First Santos-Dumont Aeroplane 44 The Cross-Channel Type Blériot Monoplane 44 A Voisin Biplane 44 Glenn Curtiss About to Make a Flight 45 Henri Farman Starting Aloft with Two Passengers 45 Louis Blériot 45 Glenn Curtiss Making a Flight in the June Bug 52 Orville Wright Making a Flight at Fort Myer 52 The First Letter Ever Written Aboard an Aeroplane in Flight 53 The Goddess of Liberty 60 First Actual War Expedition of an Aeroplane 61 War Manœuvres 61 Harry N. Atwood Arriving at Chicago 64 Finish of Atwood's St. Louis to New York Flight 64 Starting with the Aeroplane Mail 65 Chavez on His Fatal Flight Across the Alps 80 The Late Calbraith P. Rodgers, Trans-Continental Flier 81 The World's Longest Glide 96 The End of a Glide 96 Landing on a Warship 97 Boarding a Battleship 97 The Flying Boat Starting 112 The Curtiss Flying Boat 112 x Glenn Curtiss Allowing His Hydro-Aeroplane to Float on the Water After Alighting 112 Hydro-Aeroplanes at Monte Carlo 113 The Wright Biplane 116 Standard Curtiss Biplane 117 Curtiss Steering Gear 117 Standard Farman Biplane 120 Farman with Enclosed Nose 120 A Modern Blériot 121 A Standard Blériot 121 Passenger-Carrying Blériot 121 The Antoinette Monoplane 124 The Nieuport Monoplane 125 Like a Bolt of Lightning 136 Dr. Nikola Tesla 137 Doctor Tesla's First Power Plant 137 Electricity Enough to Kill an Army 164 A Battle Scene in the Studio 165 The Men Who Gave the World Motion Pictures 172 The Motion-Picture Projector 173 A Section of Motion-Picture Film 176 Making a Motion-Picture Play in the Studio 177 A Motion-Picture Studio 192 A Realistic Film of Washington Crossing the Delaware 193 The Corsican Brothers—A Famous Trick Film 200 The Guillotine 201 A Romance of the Ice Fields 216 The Spanish Cavalier 216 All Ready for a Thermit Weld 217 Thermit in Eruption 224 Dr. Hans Goldschmidt 225 Thermit Weld on Sternframe of a Steamship 240 A Large Shaft Welded by the Thermit Process 240 Cutting Up the Old Battleship Maine 241 Cutting Away the Decks 241 An Oxy-Acetylene Gas Torch Weld 260 Tiny 200-Horsepower Turbine 261 The Tesla Turbine Pump 261 The Marvellous Tesla Turbine 280 Thomas A. Edison and His Concrete Furniture 281 Model of Edison Poured Concrete House 281 What One Set of Boys Did with Concrete 288 Massive Concrete Work 289 A Level Stretch of Catskill Aqueduct 289 Huge Concrete Moulds at Panama 304 Concrete Locks on the Panama Canal 305 The World-Wide Use of Concrete 308 The Catskill Aqueduct 309 The Aqueduct Deep Under Ground 309 The Silent Knight Motor 316 A Portable Army Wireless Outfit 317 The Wireless in the Navy 317 xi xii The Navy Wireless School 344 An Amateur Wireless Outfit 345 LIST OF DIAGRAMS A Simple Model Aeroplane 120 Diagram of the Earth 147 A Motion-picture Camera 177 A Motion-picture Printing Machine 184 Diagram of the Tesla Turbine 275 The Curtiss Turbine 285 Marconi Transmitter Layout 342 Marconi Detector Layout 344 The Pulmotor 372 THE BOY'S BOOK OF NEW INVENTIONS 1 23 W CHAPTER I THE AEROPLANE HOW A SCIENTIST WHO LIKED BOYS AND A BOY WHO LIKED SCIENCE FOLLOWED THE FASCINATING STORY OF THE INVENTION OF THE AEROPLANE. HEN, with engine throbbing, propellers whirling, and every wire vibrating, the first successful aeroplane shot forward into the teeth of a biting December gale and sailed steadily over the bleak North Carolina sand dunes for twelve seconds, the third great epoch in the age of invention finally was ushered in. First, man conquered the land with locomotive, electricity, steam plow, telegraph, telephone, wireless and a thousand other inventions. Almost at the same time he conquered the ocean with steamship, cable, and wireless. Now, through the invention of the aeroplane, he is making a universal highway of the air. Such was the way the real beginning of aviation was summarized one day to a bright young man who spent all his spare time out of school at the laboratory of his good friend the scientist. Always in good humour, and with a world of knowledge of things that delight a boy's heart, the man was never too deep in experiments to answer any questions about the great inventions that have made this world of ours such a very interesting place The laboratory was filled with models of machines, queer devices for scientific experiment, a litter of delicate tools, shelves of test tubes, bottles filled with strange smelling fluids, and rows upon rows of books that looked dull enough, but which the scientist explained to the boy contained some of the most fascinating stories ever told by man. Coming back to aeroplanes the boy said, "But my father says that aviation is so new it is still very imperfect." "That is true," answered the scientist, taking a crucible out of the flame of his Bunsen burner and hanging it in the rack to cool, "but it has seen a marvellous development in the last few years. "It was less than ten years ago—the end of 1903, to be exact—that Orville and Wilbur Wright first sailed their power-driven aeroplane," he continued, "but so rapid has been the progress of aviation that nowadays we are not surprised when a flight from the Atlantic to the Pacific is accomplished. It seems a tragic thing that Wilbur Wright should have been called by death, as he was in May, 1912, by typhoid fever, for he was at the very zenith of his success and probably would have carried on his work to a far, far greater development." THE FIRST WRIGHT AEROPLANE This was the machine that made the first successful flight in the history of the world, of a power- driven, man-carrying aeroplane THE FIRST WRIGHT GLIDER This device was first flown as a kite without a pilot, and the levers worked by ropes from the ground, to test the principles THE SECOND WRIGHT GLIDER The machine was launched into the air from the top of a sand dune against a high wind, and proved a great success A LONG GLIDE Wright glider in full flight over Kill Devil Hill, N. C. After a little pause the scientist continued, saying that, at the time the Wright brothers made their first flight they were experimenting with what we now know as a biplane, or Chanute type glider, at Kill Devil Hill, near Kitty Hawk, N. C. It is a desolate wind-swept spot on the coast where only a little rank marsh grass grows on the sheltered sides of the great sand dunes. The brothers chose this barren place for their 4 5 experiments because here the winds were the most favourable for their purpose. They were not ready for their first attempt to fly in a motor-propelled machine until December 17th, and though they sent out a general invitation to the few people living in that section, only five braved the cold wind. Three of these were life savers from the Kill Devil Hill station near by. Doubtless the other people had heard of the numerous failures of flying machines and expected the promised exhibition of the silent young men who had spent the autumn in their neighbourhood, to be just another such. They were sadly mistaken, for they missed a spectacle that never before had been seen in all the history of the world. Nowadays we are familiar with the sight of an aeroplane skimming over the ground and then soaring into the sky, but to the five people who, besides the inventors, were present it undoubtedly was almost beyond belief. The brothers had installed a specially constructed gasoline engine in their glider, and after thoroughly testing it they carried the machine out on to a level stretch of sand, turned it so that it would face the wind, and while the life savers held it in place the brothers went over every wire and stay. They felt perfectly confident that the machine would fly, but they made no predictions, and in fact spoke but few words between themselves or to the five men gathered about the aeroplane. The machine was not the smoothly finished one we know to-day as the Wright biplane. The operator lay flat on his face on the lower plane, the elevating rudder composed of two smaller planes stuck out in front, instead of behind, and there were several other important differences in design, but in principle it was the same machine that has carried the fame of the American inventors around the world. Finally the operator took his place, the engine was started, the signal was given, the men holding the machine dropped back and it started out along the rail from which it was launched. It ran along the track to the end, directly against the wind, and rose into the air. It meant that the air had been turned into a highway, but the Wright brothers were very modest in setting down an account of their achievement. "The first flight," they wrote, "lasted only twelve seconds," a flight very modest compared with that of birds, but it was, nevertheless, the first in the history of the world in which a machine carrying a man had raised itself by its own power into the air in free flight, had sailed forward on a level course without reduction of speed, and had finally landed without being wrecked. The second and third flights (the same day) were a little longer, and the fourth lasted fifty-nine seconds, covering a distance of 853 feet over the ground against a twenty-mile wind. "After the last flight the machine was carried back to camp and set down in what was thought to be a safe place. But a few minutes later, when engaged in conversation about the flights, a sudden gust of wind struck the machine and started to turn it over. All made a rush to stop it, but we were too late. Mr. Daniels, a giant in stature and strength, was lifted off his feet, and, falling inside between the surfaces, was shaken about like a rattle in a box as the machine rolled over and over. He finally fell out upon the sand with nothing worse than painful bruises, but the damage to the machine caused a discontinuance of experiments." "Thus," said the scientist, we see the record aeroplane flight for 1903 was 853 feet while in 1911 a Wright biplane flew more than 3,000 miles from the Atlantic to the Pacific. In ten years more we may look back to our monoplanes and biplanes of to-day in the same way we do now on the first cumbersome 'horseless carriages' that were replaced by the high-powered automobiles we know now. Some experts in aeronautics say that we may even see the complete passing of the monoplane and biplane types in favour of some now unknown kind of aeroplane." Who knows but that the man to invent the perfect aeroplane will be one of the boy readers of this! Everywhere the making and flying of model aeroplanes by boys is looked upon, not only as play, but as a valuable and instructive sport for boys and young men of any age. One of the indications of this may be seen in the public interest taken in the tournaments of boys' model aeroplane clubs. Not only do crowds of grown people with no technical knowledge of aeroplanes attend the tournaments, but also older students of aviation who realize that among the young model fliers there may be another Orville or Wilbur Wright, a Blériot, or a Farman. So important is this knowledge of aviation considered that the principles and the practical construction of model aeroplanes are taught in many of the public schools. Instead of spending all their school hours in the study of books, the boys now spend a part of their time in the carpenter shop making the model aeroplanes which they enter in the tournaments. Of course, dozens of types of models are turned out, some good and some bad, but in the latter part of Chapter III is given a brief outline for the construction of one of the simplest and most practicable model aeroplanes. Not only the schools but the colleges also have taken up aviation, and nearly every college has its glider club, and the students work many hours making the gliders with which they contest for distance records with other clubs. As a consequence aviation has become a regular department of college athletics, and 6 7 8 9 intercollegiate glider meets are a common thing. The epochs of invention go hand in hand with the history of civilization, for it has been largely through invention that man has been able to progress to better methods of living. In the olden days, when there were few towns and every one lived in a castle, or on the land owned by the lord of the castle, war was the chief occupation, and the little communities made practically everything they used by hand. When they went abroad they either walked or rode horses, or went in clumsy ships. Pretty soon men began to invent better ways of doing things; one a better way of making shoes, another a better way of making armour, and the people for miles around would take to going to these men for their shoes and armour. Towns sprang up around these expert workmen, and more inventions came, bringing more industries to the towns. Inventions made industry bigger, and war more disastrous because of the improvement invention made in weapons. Then came inventions that changed the manner of living for all men—the machines for making cloth, which did away with the spinning-wheels of our great-grandmothers, and created the great industry of the cotton and woollen mills; the inventions for making steel that brought about the great steel mills, and enabled the armies of the world to use the great guns we know to-day, and the battleships to carry such heavy armour plate; the steam locomotive that enabled man to travel swiftly from one city to another; the steamship that brought all the nations close together; the telegraph, cable, telephone, and wireless, that made communication over any distance easy; the submarine that made war still more dangerous; and finally the aeroplane that makes a highway of the air in which our earth revolves. But even from the time of the ancient Greeks and Romans man had tried to fly. Every nation had its list of martyrs who gave their lives to the cause of aviation. In modern times, too, many attempts had been made to discover the secret of flight. Otto Lilienthal, a German, called the "Flying Man," had made important discoveries about air currents while gliding through the air from hills and walls by means of contrivances like wings fitted to his person. Others had made fairly successful gliders, and Prof. Samuel Pierepont Langley of the Smithsonian Institution in Washington actually had made a model aeroplane that flew for a short distance. Also, Clement Ader, a Frenchman, had sailed a short way in a power flier, and Sir Hiram Maxim, the English inventor, had built a gigantic steam-driven aeroplane that gave some evidences of being able to fly. But these men were laughed at as cranks, while the Wrights kept their secret until they were sure of the success of their biplane. However, the question as to who first rode in a power-driven flier under the control of the operator still is the subject of a world-wide controversy. It was as boys that the Wright brothers first began experiments with flying, and though they have received the highest praises from the whole world, Orville still is, and until his death Wilbur was, the same quiet, modest man who made bicycles in Dayton, and the surviving brother of the pair is working harder than ever. In telling the story of their own early play, that later proved to be one of the most important things they ever did, the Wright brothers wrote for the Century Magazine: "We devoted so much of our attention to kite-flying that we were regarded as experts. But as we became older we had to give up the sport as unbecoming to boys of our age." As every boy knows, kite-flying was one of the early methods of experimenting with air currents and greatly aided the scientists in their exploration of the ocean of air that surrounds the world, eddying and swirling up and down, running smoothly and swiftly here, coming to a dead stop there—but always different from the minute before. But before the Wright brothers gave up flying kites they had played with miniature flying machines. They were known then as "helicopteres," but the Wright brothers called them "bats," as the toys came nearer resembling bats than anything else the boys had seen about their home in Dayton, Ohio. Most boys probably have played with something of the kind themselves, and maybe have made some. They were made of a light framework of bamboo formed into two screws driven in opposite directions by twisted rubber bands something like the motors on boys' model aeroplanes of to-day. When the rubber bands unwound the "bats" flew upward. "A toy so delicate lasted only a short time in our hands," continues the story of the Wright brothers, "but its memory was abiding. We began building them ourselves, making each one larger than that preceding. But the larger the 'bat' the less it flew. We did not know that a machine having only twice the size of another would require eight times the power. We finally became discouraged." This was away back in 1878, and it was not until 1896 that the Wright brothers actually began the experiments that led to their world-famous success. Strangely enough it all started when Orville, the younger of the two, was sick with typhoid fever, the same disease that caused Wilbur Wright's death. According to all accounts, the elder brother, having remained away from their bicycle factory in order to nurse Orville, was reading aloud. Among other things he read to Orville the account of the tragic death of Otto Lilienthal, the German "Flying Man" who was killed while making a glide. 10 11 12 13 MOTOR OF THE WRIGHT BIPLANE A 16-CYLINDER 100-HORSEPOWER ANTOINETTE MOTOR A frequent prize winner AN 8-CYLINDER 5O-HORSEPOWER CURTISS MOTOR THE GNOME MOTOR Standard Gnome aeroplane motor, showing interior. Photo by Philip W. Wilcox Fourteen-cylinder 100-horsepower Gnome motor. Used on many racing aeroplanes. Courtesy of the Scientific American Testing a Gnome motor on a gun carriage. So great is the power of the engine that the tongue of the heavy carriage is buried in the ground to hold it in place "Why can't we make a glider that would be a success?" the brothers asked each other. They were sure they could, and they got so excited in talking it over that it nearly brought back Orville's fever. When he got well they studied aeronautics with the greatest care, approaching the subject with all the thoroughness that later made their name a byword in aviation for care and deliberation. Neither of these two young men was over demonstrative, and neither was lacking in the ability for years and years of the hardest kind of work, but together they made an ideal team for taking up the invention of something that all the scientists of the world hitherto had failed to develop. Wilbur was called by those who knew him one of the most silent men that ever lived, as he never uttered a word unless he had something to say, and then he said it in the most direct and the briefest possible manner. He had an unlimited capacity for hard work, nerves of steel and the kind of daring that makes the aviator face death with pleasure every minute of the time he is in the air. No less daring is Orville, the younger of the two, who is a little bit more talkative and more full of enthusiasm than was Wilbur. He was the man the reporters always went to when they knew the elder brother would never say a word, and his geniality never failed them. He also is a true scientist and tireless in the work of developing the art of aviation. First, the brothers read all the learned and scientific books of Professor Langley, and Octave Chanute, the two first great American pioneers in aviation, and the reports of Lilienthal, Maxim, and the brilliant French scientists. They saw, as did Professor Langley, that it was out of the question to try to make a machine that would fly by moving its wings like a bird. Then they began with great kites, and next made gliders—that is, aeroplanes without engines—for the brothers knew that there was no use in trying to make a machine- driven, heavier-than-air flier before they had tested out practically all the theories of the earlier scientists. They fashioned their gliders of two parallel main planes like those of Octave Chanute. The width, length, distance between planes, rudders, auxiliary planes and their placing were all problems for the most careful study. It was very discouraging work, for no big thing comes easily. As their experiments proceeded they said they found one rule after another incorrect, and they finally discarded most of the books the scientists had written. Then with characteristic patience they started in to work out the problem from first principles. "We had taken aeronautics merely as a sport," they wrote later. "We reluctantly entered upon the scientific side of it. But we soon found the work so fascinating that we were drawn into it deeper and deeper." The Wrights knew that an oblong plane—that is, a long narrow one—driven through the air broadside first is more evenly supported by the air than would be a plane of the same area but square in shape. The 14 15 reason for this is that the air gives the greatest amount of support to a plane at the entering edge, as it is called in aviation—that is, the edge where it is advancing into the air. A little way from the edge the air begins to slip off at the back and sides and the support decreases. Thus, it will be seen that if the rear surface, which gives little support because the air slips away from under it, is put at the sides, giving the plane a greater spread from tip to tip and not so much depth from front to rear, the plane is more efficient—that is, more stable, less subject to drifting, and better able to meet the varying wind currents. Scientists call this proportion of the spread to the depth the aspect ratio of planes. For instance, if a plane has a spread of 30 feet and a depth of 6 feet it is said to have an aspect ratio of 5. This is a very important consideration in the designing of an aeroplane, because aspect ratio is a factor in the speed. In general, high speed machines have a smaller aspect ratio than slower ones. The aspect ratio also has an important bearing on the general efficiency of an aeroplane, but the lifting power of a plane is figured as proportionate to its total area. In order to hold the air, and keep its supporting influence, aviators have tried methods of enclosing their planes like box kites, and putting edges on the under sides. This latter was found a mistake because the edge tended to decrease the speed of the flier and did more harm than the good obtained through keeping the air. In aviation, as we know it to-day, aeroplane builders believe in giving their planes a slight arch upward and backward from the entering edge, letting it reach its highest point about one third of the way back and then letting it slope down to the level of the rear edge gradually. This curve, which is called the camber, is mathematically figured out with the most painstaking care, and was one of the things the Wright brothers worked out very carefully in their early models. Also, planes are driven through the air at an angle—that is, with the entering edge higher than the rear edge—because the upward tilt gives the air current a chance to get under the plane and support it. This angle is called by the scientists the angle of incidence and is very important because of its relation to the lifting powers of the planes. MODEL AEROPLANE FLIERS Every fair Saturday the model makers and fliers spend in the parks either practising for or holding flight tournaments A MODERN COLLEGE MAN'S GLIDER OTTO LILIENTHAL MAKING A FLIGHT IN HIS GLIDER Another one of the difficult problems the inventors had to struggle with was the balance of their fliers. Before the Wright brothers flew, it was thought that one of the best ways was to incline the planes upward from the centre—that is—make them in the shape of a gigantic and very broad V. This is known in science as a dihedral angle. The idea was that the centre of gravity, or the point of the machine which is heaviest and which seeks to fall to earth first through the attraction of gravitation, should be placed immediately under the apex of the V. The scientists thought that the V then would keep the machine balanced as the hull of a ship is balanced in the water by the heavy keel at the bottom. The Wrights decided that this might be true from a scientific point of view, but that the dihedral angle kept the machine wobbling, first to one side and then righting itself, and then to the other side and righting itself. This was a practical fault and they built their flier without any attempt to have it right itself, but rather arched the planes from tip to tip as well as from front to rear. The winglike gliders of Lilienthal and Chanute had been balanced by the shifting of the operator's body, but the Wrights wanted a much bigger and safer machine than either of these pioneers had flown. In their own words, the Wrights "wished to employ some system whereby the operator could vary at will the inclination of different parts of the wings, and thus obtain from the wind forces to restore the balance which the wind itself had disturbed." This they later accomplished by a device for warping or bending their planes, but in their first glider there was no warping device and the horizontal front rudder was the only controlling device used. This latter device on the first glider was made of a smaller plane, oblong- shaped and set parallel to, and in front of, the main planes. It was adjustable through the system of levers fixed for the operator, who in those days lay flat on the front plane. Thus the two main planes and the adjustable plane in front with stays, struts, etc., made up the first Wright glider. The Wright brothers took their machine to Kitty Hawk, N. C., in October, 1900, presumably for their vacation. They went there because the Government Weather Bureau told them that the winds blew 16 17 18 stronger and steadier there than at any other point in the United States. Also it was lonely enough to suit the Wrights' desire for privacy. It was their plan to fly the contrivance like a boy does a huge box kite, and it looked something like one. A man, however, was to be aboard and operate the levers. According to the Wright brothers' story the winds were not high enough to lift the heavy kite with a man aboard, but it was flown without the operator and the levers worked from the ground by ropes. A new machine the next year showed little difference of design, but the surface of the planes was greater. Still the flier failed to lift an operator. At this time the Wright brothers were working with Octave Chanute, the Chicago inventor, engineer and scientist whom they had invited to Kitty Hawk to advise them. After many discussions with Chanute they decided that they would learn the laws of aviation by their own experience and lay aside for a time the scientific data on the subject. They began coasting down the air from the tops of sand dunes, and after the first few glides were able to slide three hundred feet through the air against a wind blowing twenty-seven miles an hour. The reason their glider flights were made against the wind was because the wind passing swiftly under the planes had the same effect as if the machine was moving forward at a good clip, for the faster the machine moves, or the faster the air passes under it, the easier it remains aloft. In other words, no one part of the air was called upon to support the planes for any length of time, but each part supported the planes for a very short time. For instance, if you are skating on thin ice you run much less danger of breaking through if you skate very fast, because no one part of the ice is called upon to support you for long. In 1902 the Wright brothers were approaching their goal. Slowly and with rare patience they were accumulating and tabulating all the different things different kinds of planes would do under different circumstances. In the fall of that year they made about one thousand gliding flights, several of which carried them six hundred feet or more. Others were made in high winds and showed the inventors that their control devices were all right. The next year, 1903, which always will be remembered as the banner one in the history of aviation, the brothers, confident that they were about to succeed in their long search for the secret of the birds, continued their soaring or gliding. Several times they remained aloft more than a minute, above one spot, supported by a high, steady wind passing under their planes. "Little wonder," wrote the Wright brothers a few years, later, "that our unscientific assistant should think the only thing needed to keep it indefinitely in the air would be a coat of feathers to make it light." What the inventors did to keep their biplane glider in the air indefinitely, however, was to add several hundred pounds to the weight in the shape of a sixteen-horsepower gasoline motor. The total weight of the machine when ready to fly was 750 pounds. Every phase of the problem had been worked out in detail—all the calculations gone over and proved both by figures and by actual test. The planes, rudders, and propellers had been designed by mathematical calculations and practical tests. The main planes of this first machine had a spread from tip to tip of 40 feet, and measured 6 feet 6 inches from the entering edge to the rear edge, a total area of 540 square feet. This will show how great is the spread of the main planes as compared to their length from front to rear. The two surfaces were set six feet apart, one directly above the other, while the elevating rudder was placed about ten feet in front of the machine on a flexible framework. This elevating rudder was composed of two parallel horizontal planes which together had an area of eighty square feet. The elevating planes could be moved up or down by the operator just as he desired to fly upward or downward. The machine was steered from right to left or left to right by two vertical vanes set at the rear of the machine about a foot apart. They were a little more than six feet long, extending from the upper supporting plane to a few inches below the lower supporting plane. These also were turned in unison by the operator, according to the direction toward which he wished to fly. The most intricate device of their machine, however, was not perfected on their first biplane. This is the one for maintaining a side to side balance, or lateral equilibrium, as the scientists say. In watching the flights of gulls, hawks, eagles, and other soaring birds, the brothers had observed that the creatures, while keeping the main part of their wings rigid, frequently would bend the extreme tips of their wings ever so slightly, which would seem to straighten their bodies in the air. The inventor decided that they needed some such device as nature had given to these birds. The system was called by the scientists the torsional wing system, which means that the tip ends of the wings were flexible and could be warped or bent or curled up or down at will by the operator. Only the rear part of the tips of the wings on the Wright machines could be bent, but this was enough to keep the machine on an even keel when properly manipulated. How the Wright modern machines are operated is fully described on page (99). The whole machine was mounted on a pair of strong light wooden skids like skiis or sled-runners. To start the early Wright biplanes, the machines were placed on a monorail, along which they were towed by a cable. The force for towing them at sufficient speed was obtained by dropping from the top 19 20 21 22 of a derrick built at the rear of the rail a ton of iron which was connected with the cable. The later Wright biplanes were equipped with rubber-tired wheels mounted on the framework, which still retained the skids. Heavy rubber springs were provided to absorb the shock. With the wheels the machine could run over the ground of its own power and thus the cumbersome derrick and monorail were done away with. The operator was supposed to lie on his face in the middle of the lower plane, but in the later machines a seat was provided for him alongside the engine, and in still later ones seats for one or two passengers. The engine which was designed by the Wright brothers themselves for this purpose, was a water-cooled four-cylinder motor which developed sixteen horsepower from 1,020 revolutions per minute. The engine was connected with the propellers at the rear of the biplane by chains. The propellers were about eight feet in diameter and the blades were six to eight inches wide. The materials used in the biplane were mostly durable wood like spruce pine and ash, the metal in the engine and the canvas on the planes. There was not one superfluous wire. Everything had a use, and even the canvas was stretched diagonally that it might fit more tightly over the framework of the planes and offer less wind resistance, and also stretch more easily for the wing warping. Finally on December 17, 1903, everything was in readiness for the first attempt of these two patient men —then unknown to the world—to fly in a power-driven machine. That first flight, made practically in secret amid the desolate sand dunes of the North Carolina coast, lasted only twelve seconds. However, it was the first time, but one, in the history of the world that a machine carrying a man had lifted itself from the ground and flown entirely by its own power. The two succeeding flights were longer, and the fourth covered 853 feet, lasting fifty-nine seconds. The inventors were not heralded as the greatest men of their time. There were no medals or speeches. The five men—fishermen and life savers—who saw the flights agreed that it was wonderful, but they kept the Wrights' secret and the brothers calmly continued their studies and experiments. The spring of 1904 found them at work on Huffman Prairie about eight miles east of Dayton. The first trials there were not very successful and the brothers, who had worked seven long years in secret, had the unpleasant experience of failing to show satisfactory results to the few friends and reporters invited to see an aeroplane flight. Their new machine was larger, heavier, and stronger, but the engine failed to work properly. Of course this was no great disappointment to those two silent, determined young men. "We are not circus performers," they said. "Our aim is to advance the science of aviation." And advance it they did. Their experiments continued, and in 1904 they made a record of three miles in 5 minutes 27 seconds. The next year, 1905, they made a record flight of 24.20 miles and remained in the air 38 minutes 13 seconds at heights of from 75 to 100 feet. All this time the brothers were solving problems and correcting faults, but in 1904 and 1905 their chief endeavour was to keep their machines from tipping sidewise when they turned. Only the most technical study and the final development of their wing-warping device solved the problem. Perhaps the strangest part was the lack of interest shown in their work by the world and even by their own townsmen, for, though there had been several newspaper accounts of their test flights, no great enthusiasm was aroused. They were not wealthy and they had spent more on their experiments than they could afford, so all this time they had proceeded without attracting any more attention than necessary. They desired to perfect their patents before letting the world know the secret of their inventions, and spent the next two years in business negotiations. Meanwhile, the French inventors were making much progress and soon brought out several successful aeroplanes. Why was this? Why was it that the art of air navigation sought by man since the earliest times should have been discovered and mastered so quickly? The answer lies in the putting together of two things by the Wright brothers—that is, their discovery of the kind of a plane that would stay aloft with the air passing under it at a swift enough clip to give it support, and their adaptation of the gasoline engine to the use of driving the plane forward with enough speed. When they began work, the gasoline engine was just coming to its real development. It was light, developed a high power, and its fuel could be concentrated into a small space. These things were essential to the success of the aeroplane—light weight, high power, and concentrated fuel. And these 23 24 25 26